A train covers a certain distance moving at a speed of 60 km/h. However it will halt for fixed time interval in each hour, its average speed reduced to 50 km/h. For how much time does the train halt for every hour?

Options

A. 6 min
B. 10 min
C. 12 min
D. none of these

Answer

To solve the problem, we need to determine how long the train halts for every hour given its speeds with and without halting.

### Step-by-Step Solution:

1. **Identify the Speeds**:
- The speed of the train without halting is 60 km/h.
- The average speed of the train after halting is 50 km/h.

2. **Set Up the Ratio of Speeds**:
- The ratio of the speeds is given by:
\[ \text{Speed Ratio} = \frac{60}{50} = \frac{6}{5} \]

3. **Determine the Time Ratio**:
- Since distance is constant, speed is inversely proportional to time. Therefore, the time ratio can be calculated as:
\[ \text{Time Ratio} = \frac{1/6}{1/5} = \frac{5}{6} \]
- This means that for every 5 units of time taken without halting, it now takes 6 units of time when halting.

4. **Interpret the Time Ratio**:
- If we assume that the original time taken to cover a certain distance is 5 hours, then the new time taken when halting is 6 hours. This indicates that the train halts for 1 hour over the course of 6 hours.

5. **Calculate the Halting Time per Hour**:
- Since the train halts for 1 hour in 6 hours, the halting time per hour is:
\[ \text{Halting Time per Hour} = \frac{1 \text{ hour}}{6 \text{ hours}} = \frac{1}{6} \text{ hours} \]

6. **Convert Halting Time to Minutes**:
- To convert the halting time from hours to minutes, we multiply by 60:
\[ \text{Halting Time in Minutes} = \frac{1}{6} \times 60 = 10 \text{ minutes} \]

### Final Answer:
The train halts for **10 minutes** every hour.

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